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Finding the Fourth Proportional to 643.96, 965.89 and 211.06

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Solution

The fourth proportional to 643.96, 965.89 and 211.06 is: 316.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.96 : 965.89 = 211.06 : x
  2. Step 2: Convert to fraction form
    643.96/965.89 = 211.06/x
  3. Step 3: Cross multiply
    643.96x = 965.89 × 211.06
  4. Step 4: Simplify right side
    643.96x = 203,860.74
  5. Step 5: Solve for x
    x = 203,860.74/643.96
  6. Step 6: Final answer
    x = 316.57

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.